Aptasensor-enabled quantitative analysis of nano-sized extracellular vesicles by flow cytometry

The Analyst ◽  
2020 ◽  
Vol 145 (23) ◽  
pp. 7551-7558
Author(s):  
Jing Du ◽  
Chao Yuan ◽  
Weijie Wang ◽  
Zitong Yu ◽  
Rui Hao ◽  
...  

Flow cytometry analysis of extracellular vesicles enabled by an aptamer-based biosensor to interact with tetraspanin CD63 proteins.

HortScience ◽  
2011 ◽  
Vol 46 (11) ◽  
pp. 1465-1467
Author(s):  
Ryan N. Contreras ◽  
Ron Determann ◽  
Mara Friddle

There is a great deal of variation among japanese-cedar cultivars with regard to growth form, foliar characteristics, and winter browning. Differences in winter browning have been observed and documented by a number of authors. Previous research has established that there are differences in winter foliage color between cultivars included in the current study; however, no quantitative analysis under standardized conditions was conducted. Because of a previous report that tetraploid forms of japanese-cedar remain green during winter as a result of increased antioxidant enzyme activity, we hypothesized that cultivars that exhibit reduced winter browning were polyploids. We screened 56 accessions of japanese-cedar using flow cytometry analysis of 4′,6-diamidino-2-phenylindole (DAPI)-stained nuclei and performed chromosome counts on three cultivars. All accessions were diploid (2n = 2x = 22), although there were significant differences in genome sizes among the cultivars. Holoploid genome sizes ranged from 18.9 pg for var. sinensis JCRA to 22.3 pg for ‘Viridis’ with a mean of 20.1 pg. Chromosome counts for cultivars Ogon, Oye Keme, and Viridis supported the flow cytometry results. Although the underlying cause of the variability in morphology and winter browning among cultivars is unclear, our results show that differences in ploidy level are not responsible, because all tested genotypes were diploid. Chemical name: 4′,6-diamidino-2-phenylindole (DAPI).


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Henar Suárez ◽  
Ana Gámez-Valero ◽  
Raquel Reyes ◽  
Soraya López-Martín ◽  
María Josefa Rodríguez ◽  
...  

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 124
Author(s):  
Jaco Botha ◽  
Haley R. Pugsley ◽  
Aase Handberg

Flow cytometry remains a commonly used methodology due to its ability to characterise multiple parameters on single particles in a high-throughput manner. In order to address limitations with lacking sensitivity of conventional flow cytometry to characterise extracellular vesicles (EVs), novel, highly sensitive platforms, such as high-resolution and imaging flow cytometers, have been developed. We provided comparative benchmarks of a conventional FACS Aria III, a high-resolution Apogee A60 Micro-PLUS and the ImageStream X Mk II imaging flow cytometry platform. Nanospheres were used to systematically characterise the abilities of each platform to detect and quantify populations with different sizes, refractive indices and fluorescence properties, and the repeatability in concentration determinations was reported for each population. We evaluated the ability of the three platforms to detect different EV phenotypes in blood plasma and the intra-day, inter-day and global variabilities in determining EV concentrations. By applying this or similar methodology to characterise methods, researchers would be able to make informed decisions on choice of platforms and thereby be able to match suitable flow cytometry platforms with projects based on the needs of each individual project. This would greatly contribute to improving the robustness and reproducibility of EV studies.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1461
Author(s):  
Nuno Mariz-Ponte ◽  
Laura Regalado ◽  
Emil Gimranov ◽  
Natália Tassi ◽  
Luísa Moura ◽  
...  

Pseudomonas syringae pv. actinidiae (Psa) is the pathogenic agent responsible for the bacterial canker of kiwifruit (BCK) leading to major losses in kiwifruit productions. No effective treatments and measures have yet been found to control this disease. Despite antimicrobial peptides (AMPs) having been successfully used for the control of several pathogenic bacteria, few studies have focused on the use of AMPs against Psa. In this study, the potential of six AMPs (BP100, RW-BP100, CA-M, 3.1, D4E1, and Dhvar-5) to control Psa was investigated. The minimal inhibitory and bactericidal concentrations (MIC and MBC) were determined and membrane damaging capacity was evaluated by flow cytometry analysis. Among the tested AMPs, the higher inhibitory and bactericidal capacity was observed for BP100 and CA-M with MIC of 3.4 and 3.4–6.2 µM, respectively and MBC 3.4–10 µM for both. Flow cytometry assays suggested a faster membrane permeation for peptide 3.1, in comparison with the other AMPs studied. Peptide mixtures were also tested, disclosing the high efficiency of BP100:3.1 at low concentration to reduce Psa viability. These results highlight the potential interest of AMP mixtures against Psa, and 3.1 as an antimicrobial molecule that can improve other treatments in synergic action.


Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1320
Author(s):  
Kristýna Pekárková ◽  
Jakub Soukup ◽  
Marie Kostelanská ◽  
Jan Širc ◽  
Zbyněk Straňák ◽  
...  

Extracellular vesicles (EVs) from liquid biopsies are extensively analyzed by flow cytometry, a technology that is continuously evolving. Thresholding utilizing a violet 405 nm laser side scatter (VSSC) has recently been implemented. Here, we collected set of large EV (lEV) samples from cord blood, which we analyzed using a standard flow cytometer improved via a 405 nm laser side scatter. Samples were analyzed using two distinct thresholding methods—one based on VSSC, and one based on VSSC combined with fluorescence thresholding on stained phosphatidylserine. Through these thresholding methods, we compared lEVs from pre-term births and control cord blood. Double-labeled lEVs with platelet CD36+/CD41+, activated platelet CD41+/CD62P+ and endothelial CD31+/CD105+ antibodies were used. Apart from comparing the two groups together, we also correlated measured lEVs with the thresholding methods. We also correlated the results of this study with data analyzed in our previous study in which we used a conventional 488 nm laser SSC. We did not find any difference between the two cord blood groups. However, we found highly concurrent data via our correlation of the thresholding methods, with correlation coefficients ranging from 0.80 to 0.96 even though the numbers of detected lEVs differed between thresholding methods. In conclusion, our approaches to thresholding provided concurrent data and it seems that improving the cytometer with the use of a VSSC increases its sensitivity, despite not being particularly critical to the validity of flow cytometric studies that compare pathological and physiological conditions in liquid biopsies.


Sign in / Sign up

Export Citation Format

Share Document